DOE aims to store CO2 and recover CH4 simultaneously

The US Department of Energy and its Southwest Regional Partnership recently began to inject carbon dioxide into a large coalbed while recovering natural gas, DOE's Fossil Energy Office announced on last month. It is said that the planned injection of CO2 in a sic month demonstration near Navajo City, NM, differs from other enhanced CBM recovery projects because it will attempt to maximize permanent storage of the CO2 in a process called geologic carbon sequestration using process known as enhanced coal-bed methane recovery.

 

Many coalbeds in the United States are saturated with natural gas (methane), but the gas is difficult to produce because methane typically binds to coal. However, CO2 shares the same tendency and injecting it into the coalbed essentially displaces the methane and makes the gas easier to produce.

Favorable geology, high methane content, available CO2 from nearby power plants, low capital and operating costs, and well-developed natural gas and CO2 pipelines made the San Juan Basin, which is considered one of the top-ranked basins worldwide for CBM, a prime candidate for value-added CO2 sequestration. Due to the tendency of coal to swell when in contact with CO2, high initial coal permeability is required to maintain CO2 injection rates (high injectivity) over time.